Deneysel beyin iskemisinde Tacrolimus' un Endotelin?1, Melatonin ve Heat shock protein?70 seviyelerine etkisi

Stroke is the third major cause of death in the industrialized countries after cardiovascular disease and cancer. Neuroprotection may be an alternative strategy for the treatment of ischemic stroke and may limit the extent of irreversible damage that occurs to the neuronal cells surrounding the site of an infarction. Immunosuppressant Tacrolimus is neuroprotective in experimental models of cerebral ischemia, but the molecular mechanisms underlying this neuroprotection remain unknown. The aim of this study is to investigate the effects of Tacrolimus on plasma endothelin-1 and melatonin and brain Hsp-70 levels in experimental ischemic strokeThree groups each one included seven Wistar albino rats were formed. Animals in group 2 (sham) and group 3 (study) were anesthetized and bilateral common carotid arteries were clamped with aneurysm clips for 10 minutes. Animals in group 1 (control) were not clamped and were not given any treatment. Rats in group 2 were received 1 ml saline and in group 3 were received 1 mg/kg Tacrolimus intraperitoneally. Injections were applied 1 hour before ischemia and at 6, 24, 48 and 72 th hours post ischemia. All the animals were decapitated on the 4th day and plasmas were obtained and brains were excised. Plasma endothelin-1 and melatonin levels were measured. Brain Hsp-70 immunostaining and neuron cell death were scored semicantitatively.The plasma endothelin-1 levels in group 3 was higher than group 2 and group 1, but was similar in group 1 and group 2. In group 1 plasma melatonin levels was lesser than group 2 and group 3. In group 2 plasma melatonin levels was higher than group 3. The mean neuron death in group 3 was lesser than in group 2. The mean Hsp-70 immunostaining intensity in group 2 was greater than group 3 and group 1. In group 1 the mean Hsp-70 immünostaining intensity was lesser than group 3.Tacrolimus administration in ischemic stroke reduces plasma melatonin and brain Hsp-70 levels and increases plasma endothelin-1 levels and has neuroprotective effect.Key words: Endothelin-1, Heat Shock Protein-70, melatonin, ischemic stroke